Centrifuge having a rotation-sensitive pumping device

ABSTRACT

A rotation-sensitive pumping device for pumping liquid from one part of a centrifuge to another during rotation thereof comprises a diaphragm mounted on the centrifuge rotor and moveable from one position to another as a function of rotor speed to pump the liquid. The diaphragm is disposed at an angle between two rotating chambers of the centrifuge and, at a given angular velocity of the rotor, the diaphragm is moved by centrifugal force from one position to the other to pump the liquid from one chamber to the other. The diaphragm may include two flexible diaphragms separated by a cavity filled with a fluid. A partition wall may be located in the space between the diaphragms forming cavities between the partition wall and each diaphragm. An aperture is provided in the partition wall for the passage of fluid between the two cavities on motion of the diaphragms.

United States Patent 1 Unger et a1.

[451 Aug. 15, 1972 CENTRIFUGE HAVING A ROTATION- SENSITIVE PUMPINGDEVICE Inventors: Hans'Peter Olof Unger, Stockholm;

Johan Eric Hayden Westberg, Lidingo, both of Sweden Assignee: AGAAktiebolag, Lidingo, Sweden Filed: Aug. 6, 1970 Appl. No.: 61,573

Foreign Application Priority Data Aug. 11, 1969 Sweden ..l l 119/69 US.Cl. ..233/20 R Int. Cl. ..B04b 11/00 Field of Search ..233/26, 27, 28,29, 35, 39,

References Cited UNITED STATES PATENTS 12/1953 Abbott ..233/27 Peck..233/9 MacRlind .L.233/20 Primary Examiner-.lordan Franklin AssistantExaminer-George H. Krizmanich Attorney-Larson, Taylor and Hinds 5 7 1ABSTRACT A rotation-sensitive pumping device for pumping liquid from onepart of a centrifuge to another during I rotation thereof comprises adiaphragm mounted on the centrifuge rotor and moveable from one positionto another as a function of rotor speed to pump the liquid. Thediaphragm is disposed at an angle between two rotating chambers of thecentrifuge and, at a given angular velocity of the rotor, the diaphragmis moved by centrifugal force from one position to the other to pump theliquid from one chamber to the other. The diaphragm may include twoflexible diaphragms separated'by a cavity filled with a fluid. Apartition wall may be located in the space between the diaphragmsforming cavities between the partition wall and each diaphragm. Anaperture is provided in the partition wall for the passage of fluidbetween the two cavities on motion of the diaphragms.

, 6 Claims, 2 Drawing Figures PATENTED M18 15 I972 INVENTORS HANS P. O.UNGER JOHAN E. H. WESTBERG fi Z50c03 7/eg BY AT TOR NEYS CENTRIFUGEHAVING A ROTATION-SENSITIVE PUMPING DEVICE BACKGROUND OF THE INVENTIONThe invention relates to a rotation-sensitive pumping device forcentrifuges. More particularly, the invention relates to such devicesfor the transfer of liquid from one portion of a centrifuge to anotherportion during rotation thereof.

In centrifuges where a pumping effect is' desired for the transfer of aliquid from one part of the centrifuge to another, a simplification ofthe working procedure can be achieved by making the pumping effectdependent on the number of revolutions. Governor devices depending onthe speed of revolutions and utilizing weights are well-known for thispurpose. It is an object of the present invention to provide asimplified speeddependent pumping device of this type.

BRIEF SUMMARY OF THE PRESENT INVENTION The foregoing and other objectswhich will be apparent to those having ordinary skill in the art areachieved according to the present invention by providing arotation-sensitive pumping device for pumping a liquid from one part ofthe centrifuge to another during rotation thereof comprising adiaphragm, means for mounting the diaphragm on a centrifuge rotor torevolve therewith, said diaphragm being responsive 'to the angularvelocity of said rotor to move between first and second positions as afunction of angular velocity of said rotor, said diaphragm beingpositioned to pump said liquid between said parts of said centrifugeupon motion of said diaphragm between said first and second positions.

DETAILED DESCRIPTION There follows a detailed description of a preferredembodiment of the invention, together with accompanying drawings.However, it is to be understood that the detailed description andaccompanying drawings are provided solely for the purpose ofillustrating a preferred embodiment and that the invention is capable ofnumerous modifications and variations apparent to those skilled in theart without departing from the spirit and scope of the invention.

FIG. 1 is a schematic side elevation, in section, of a pumping deviceaccording to the present invention.

FIG. 2 is a cross-sectional view of a weighted diaphragm useful in thedevice of FIG. 1.

A centrifuge rotor 1 or a part there of comprises a plate 2 of anon-flexible material which is penetrated by an opening 3. On the upperside of the plate is situated a rubber diaphragm 4 and on the lower sidea similar rubber diaphragm 5. Both diaphragms are annular and matched tothe plate and fixed at the inner and outer edges thereof as can be seenin the figure. Between the diaphragms a cavity 6 is formed in which is aliquid. A cover 7 of heavy material is fixed to diaphragm so as toincrease the weight of the diaphragm and thus increase the sensitivityof the diaphragm to the speed of rotation. The same result can beachieved by incorporating a heavy material 12 (FIG. 2) blended with therubber itself in the diaphragm 5. Not only the diaphragm 5 but also thediaphragm 4 may be loaded so as to increase its weight. The loadin issuch that the diaphragms are given a substantial y higher specificgravity than the liquid which is to be transferred.

Above the diaphragm 4 is a chamber 8 and below the diaphragm 5 is asimilar chamber 9. Both chambers 8 and 9 are interconnected by a tube 10and both are mounted for rotation on rotor 1.

The volume of the displacement fluid in the space 6 is matched to theamount of liquid which is intended for transfer from one of the chambers8, 9 to the other. The diaphragms 4 and 5 may have annular shape, andbeing clamped along the edges as shown in the figure, the diaphragmswill then, if no rotation takes place, be curved downwards as shown.

In the arrangement described, diaphragms 4 and 5 will assume theposition as shown in the figure at rest and at low speed. If the speedexceeds a certain value, the centrifugal force on the diaphragm 5ultimately becomes sufficient that it is pressed upwards and outwardswhich'causes the displacement fluid to be moved into the interspacebetween the plate 2 and the diaphragm 4. A corresponding amount of fluidis simultaneously pumped from chamber 8 to chamber 9 through conduit 10.

Through appropriate selection of the bias and weight of the diaphragm inrelation to the specific gravity of the pumped liquid the value of speedmay be selected at whith the transition from one position to the otheroccurs.

The device is particularly useful in a centrifuge of the type describedin U.S. application Ser. No. 6l, 5 83 filed Aug. 6, 1970 which is hereinincorporated by reference.

What is claimed is: y

1. In a centrifuge having-a rotor, first and. second chambers for liquidto be centrifuged connected to said rotor for rotation therewith, aconduit for said liquid interconnecting said chambers, and a rotationsensitive pumping device for pumping a liquid from one chamber to theother during the rotation thereof, wherein said pumping device comprisesdiaphragm means interposed between said chambers for rotation with saidrotor, said diaphragm means including a diaphragm moveable between firstand second positions as a function of angular velocity of said rotor topump liquid from one of said chambers to the other.

2. An improved centrifuge according to claim 1 wherein said diaphragm isconical in cross section.

3. An improved centrifuge according to claim 2 wherein said diaphragmmeans comprises a second diaphragm spaced from the said diaphragmdefining a cavity between said diaphragms, said cavity being filled

1. In a centrifuge having a rotor, first and second chambers for liquidto be centrifuged connected to said rotor for rotation therewith, aconduit for said liquid interconnecting said chambers, and a rotationsensitive pumping device for pumping a liquid from one chamber to theother during the rotation thereof, wherein said pumping device comprisesdiaphragm means interposed between said chambers for rotation with saidrotor, said diaphragm means including a diaphragm moveable between firstand second positions as a function of angular velocity of said rotor topump liquid from one of said chambers to the other.
 2. An improvedcentrifuge according to claim 1 wherein said diaphragm is conical incross section.
 3. An improved centrifuge according to claim 2 whereinsaid diaphragm means comprises a second diaphragm spaced from the saiddiaphragm defining a cavity between said diaphragms, said cavity beingfilled with a fluid.
 4. An improved centrifuge according to claim 3wherein said cavity is divided by a rigid partition wall defining acavity between each of said diaphragms and said partition wall, saidpartition wall including an aperture interconnecting the cavities.
 5. Animproved centrifuge according to claim 2 wherein said diaphragmcomprises a flexible diaphragm material and a weight increasing materialsecured thereto.
 6. An improved centrifuge according to claim 2 whereinsaid diaphragm comprises a flexible diaphragm material incorporating aweight increasing material.